/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/

This software is provided 'as-is', without any express or implied warranty.
In no event will the authors be held liable for any damages arising from the use of this software.
Permission is granted to anyone to use this software for any purpose, 
including commercial applications, and to alter it and redistribute it freely, 
subject to the following restrictions:

1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/



#define CUBE_HALF_EXTENTS 1

#define EXTRA_HEIGHT 1.f

#include "CcdPhysicsDemo.h"
#include "GlutStuff.h"
#include "GLDebugFont.h"

///btBulletDynamicsCommon.h is the main Bullet include file, contains most common include files.
#include "btBulletDynamicsCommon.h"

#include <stdio.h> //printf debugging
#include "GLDebugDrawer.h"

#if 0
extern btAlignedObjectArray<btVector3> debugContacts;
extern btAlignedObjectArray<btVector3> debugNormals;
#endif 

static GLDebugDrawer	sDebugDrawer;


CcdPhysicsDemo::CcdPhysicsDemo()
:m_ccdMode(USE_CCD)
{
	setDebugMode(btIDebugDraw::DBG_DrawText+btIDebugDraw::DBG_NoHelpText);
	setCameraDistance(btScalar(40.));
}


void CcdPhysicsDemo::clientMoveAndDisplay()
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 

	//simple dynamics world doesn't handle fixed-time-stepping
	//float ms = getDeltaTimeMicroseconds();
	
	///step the simulation
	if (m_dynamicsWorld)
	{
		m_dynamicsWorld->stepSimulation(1./60.,0);//ms / 1000000.f);
		//optional but useful: debug drawing
		m_dynamicsWorld->debugDrawWorld();
	}
		
	renderme(); 

	displayText();
#if 0
	for (int i=0;i<debugContacts.size();i++)
	{
		getDynamicsWorld()->getDebugDrawer()->drawContactPoint(debugContacts[i],debugNormals[i],0,0,btVector3(1,0,0));
	}
#endif

	glFlush();

	swapBuffers();

}


void CcdPhysicsDemo::displayText()
{
	int lineWidth=440;
	int xStart = m_glutScreenWidth - lineWidth;
	int yStart = 20;

	if((getDebugMode() & btIDebugDraw::DBG_DrawText)!=0)
	{
		setOrthographicProjection();
		glDisable(GL_LIGHTING);
		glColor3f(0, 0, 0);
		char buf[124];
		
		glRasterPos3f(xStart, yStart, 0);
		switch (m_ccdMode)
		{
		case USE_CCD:
			{
				sprintf(buf,"Predictive contacts and motion clamping");
				break;
			}
		case USE_NO_CCD:
			{
				sprintf(buf,"CCD handling disabled");
				break;
			}
		default:
			{
				sprintf(buf,"unknown CCD setting");
			};
		};

		GLDebugDrawString(xStart,20,buf);
		glRasterPos3f(xStart, yStart, 0);
		sprintf(buf,"Press 'p' to change CCD mode");
		yStart+=20;
		GLDebugDrawString(xStart,yStart,buf);
		glRasterPos3f(xStart, yStart, 0);
		sprintf(buf,"Press '.' or right mouse to shoot bullets");
		yStart+=20;
		GLDebugDrawString(xStart,yStart,buf);
		glRasterPos3f(xStart, yStart, 0);
		sprintf(buf,"space to restart, h(elp), t(ext), w(ire)");
		yStart+=20;
		GLDebugDrawString(xStart,yStart,buf);
		
		resetPerspectiveProjection();
		glEnable(GL_LIGHTING);
	}	

}



void CcdPhysicsDemo::displayCallback(void) {

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
	
	renderme();

	displayText();

	//optional but useful: debug drawing to detect problems
	if (m_dynamicsWorld)
	{
		m_dynamicsWorld->debugDrawWorld();
	}
#if 0
	for (int i=0;i<debugContacts.size();i++)
	{
		getDynamicsWorld()->getDebugDrawer()->drawContactPoint(debugContacts[i],debugNormals[i],0,0,btVector3(1,0,0));
	}
#endif

	glFlush();
	swapBuffers();
}





void	CcdPhysicsDemo::initPhysics()
{
	setTexturing(true);
	setShadows(true);
	
	m_ShootBoxInitialSpeed = 4000.f;

	m_defaultContactProcessingThreshold = 0.f;
	GraphicsPhysicsBridge bridge;
	m_physicsSetup.initPhysics(bridge);
	m_dynamicsWorld = m_physicsSetup.m_dynamicsWorld;
	m_dynamicsWorld->getSolverInfo().m_solverMode |=SOLVER_USE_2_FRICTION_DIRECTIONS|SOLVER_RANDMIZE_ORDER;
		
	m_dynamicsWorld ->setDebugDrawer(&sDebugDrawer);

	//m_dynamicsWorld->getSolverInfo().m_splitImpulse=false;
	


	if (m_ccdMode==USE_CCD)
	{
		m_dynamicsWorld->getDispatchInfo().m_useContinuous=true;
	} else
	{
		m_dynamicsWorld->getDispatchInfo().m_useContinuous=false;
	}

	m_dynamicsWorld->setGravity(btVector3(0,-10,0));

}

void	CcdPhysicsDemo::clientResetScene()
{
	exitPhysics();
	initPhysics();
}

void CcdPhysicsDemo::keyboardCallback(unsigned char key, int x, int y)
{
	if (key=='p')
	{
		switch (m_ccdMode)
		{
			case USE_CCD:
			{
				m_ccdMode = USE_NO_CCD;
				break;
			}
			case USE_NO_CCD:
			default:
			{
				m_ccdMode = USE_CCD;
			}
		};
		clientResetScene();
	} else
	{
		DemoApplication::keyboardCallback(key,x,y);
	}
}


void	CcdPhysicsDemo::shootBox(const btVector3& destination)
{

	if (m_dynamicsWorld)
	{
		float mass = 1.f;
		btTransform startTransform;
		startTransform.setIdentity();
		btVector3 camPos = getCameraPosition();
		startTransform.setOrigin(camPos);

		setShootBoxShape ();


		btRigidBody* body = this->localCreateRigidBody(mass, startTransform,m_shootBoxShape);
		body->setLinearFactor(btVector3(1,1,1));
		//body->setRestitution(1);

		btVector3 linVel(destination[0]-camPos[0],destination[1]-camPos[1],destination[2]-camPos[2]);
		linVel.normalize();
		linVel*=m_ShootBoxInitialSpeed;

		body->getWorldTransform().setOrigin(camPos);
		body->getWorldTransform().setRotation(btQuaternion(0,0,0,1));
		body->setLinearVelocity(linVel);
		body->setAngularVelocity(btVector3(0,0,0));
		body->setContactProcessingThreshold(1e30);

		///when using m_ccdMode, disable regular CCD
		if (m_ccdMode==USE_CCD)
		{
			body->setCcdMotionThreshold(CUBE_HALF_EXTENTS);
			body->setCcdSweptSphereRadius(0.4f);
		}
		
	}
}




void	CcdPhysicsDemo::exitPhysics()
{
	m_physicsSetup.exitPhysics();


	
}




